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2020-08-12selftests: kmod: use variable NAME in kmod_test_0001()Tiezhu Yang1-2/+2
Patch series "kmod/umh: a few fixes". Tiezhu Yang had sent out a patch set with a slew of kmod selftest fixes, and one patch which modified kmod to return 254 when a module was not found. This opened up pandora's box about why that was being used for and low and behold its because when UMH_WAIT_PROC is used we call a kernel_wait4() call but have never unwrapped the error code. The commit log for that fix details the rationale for the approach taken. I'd appreciate some review on that, in particular nfs folks as it seems a case was never really hit before. This patch (of 5): Use the variable NAME instead of "\000" directly in kmod_test_0001(). Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Sergei Trofimovich <slyfox@gentoo.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Sergey Kvachonok <ravenexp@gmail.com> Cc: Tony Vroon <chainsaw@gentoo.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Link: http://lkml.kernel.org/r/20200610154923.27510-1-mcgrof@kernel.org Link: http://lkml.kernel.org/r/20200610154923.27510-2-mcgrof@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-17selftests: kmod: Add module address visibility testKees Cook1-0/+36
Make sure we don't regress the CAP_SYSLOG behavior of the module address visibility via /proc/modules nor /sys/module/*/sections/*. Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-kselftest@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-07-09Replace HTTP links with HTTPS ones: KMOD KERNEL MODULE LOADER - USERMODE HELPERAlexander A. Klimov1-1/+1
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-04-10selftests: kmod: test disabling module autoloadingEric Biggers1-0/+30
Test that request_module() fails with -ENOENT when /proc/sys/kernel/modprobe contains (a) a nonexistent path, and (b) an empty path. Case (b) is a regression test for the patch "kmod: make request_module() return an error when autoloading is disabled". Tested with 'kmod.sh -t 0010 && kmod.sh -t 0011', and also simply with 'kmod.sh' to run all kmod tests. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: NeilBrown <neilb@suse.com> Link: http://lkml.kernel.org/r/20200312202552.241885-5-ebiggers@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-10selftests: kmod: fix handling test numbers above 9Eric Biggers1-4/+9
get_test_count() and get_test_enabled() were broken for test numbers above 9 due to awk interpreting a field specification like '$0010' as octal rather than decimal. Fix it by stripping the leading zeroes. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: NeilBrown <neilb@suse.com> Link: http://lkml.kernel.org/r/20200318230515.171692-5-ebiggers@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-23selftests: kmod: Fix typo in kmod.shMasanari Iida1-3/+3
This patch fixes some spelling typos in kmod.sh Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30selftests: kmod: return Kselftest Skip code for skipped testsShuah Khan (Samsung OSG)1-5/+8
When kmod test is skipped because of unmet dependencies and/or unsupported configuration, it returns 0 which is treated as a pass by the Kselftest framework. This leads to false positive result even when the test could not be run. It returns fail in some cases when test is skipped. Either way, it is incorrect and incosnistent reporting. Change it to return kselftest skip code when a test gets skipped to clearly report that the test could not be run. Kselftest framework SKIP code is 4 and the framework prints appropriate messages to indicate that the test is skipped. Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org> Reviewed-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
2017-08-18test_kmod: fix description for -s -and -c parametersLuis R. Rodriguez1-2/+2
The descriptions were reversed, correct this. Link: http://lkml.kernel.org/r/20170809234635.13443-4-mcgrof@kernel.org Fixes: 64b671204afd71 ("test_sysctl: add generic script to expand on tests") Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Reported-by: Daniel Mentz <danielmentz@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: David Binderman <dcb314@hotmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matt Redfearn <matt.redfearn@imgetc.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Michal Marek <mmarek@suse.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-07test_kmod: fix kmod.sh by making it executableLuis R. Rodriguez1-0/+0
We had just forgotten to do this. Without this if we run the following we get a permission denied: sudo make -C tools/testing/selftests/kmod/ run_tests make: Entering directory '/home/mcgrof/linux-next/tools/testing/selftests/kmod' /bin/sh: ./kmod.sh: Permission denied selftests: kmod.sh [FAIL] /home/mcgrof/linux-next/tools/testing/selftests/kmod make: Leaving directory '/home/mcgrof/linux-next/tools/testing/selftests/kmod Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader") Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-07-14kmod: throttle kmod thread limitLuis R. Rodriguez1-22/+2
If we reach the limit of modprobe_limit threads running the next request_module() call will fail. The original reason for adding a kill was to do away with possible issues with in old circumstances which would create a recursive series of request_module() calls. We can do better than just be super aggressive and reject calls once we've reached the limit by simply making pending callers wait until the threshold has been reduced, and then throttling them in, one by one. This throttling enables requests over the kmod concurrent limit to be processed once a pending request completes. Only the first item queued up to wait is woken up. The assumption here is once a task is woken it will have no other option to also kick the queue to check if there are more pending tasks -- regardless of whether or not it was successful. By throttling and processing only max kmod concurrent tasks we ensure we avoid unexpected fatal request_module() calls, and we keep memory consumption on module loading to a minimum. With x86_64 qemu, with 4 cores, 4 GiB of RAM it takes the following run time to run both tests: time ./kmod.sh -t 0008 real 0m16.366s user 0m0.883s sys 0m8.916s time ./kmod.sh -t 0009 real 0m50.803s user 0m0.791s sys 0m9.852s Link: http://lkml.kernel.org/r/20170628223155.26472-4-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-14kmod: add test driver to stress test the module loaderLuis R. Rodriguez3-0/+653
This adds a new stress test driver for kmod: the kernel module loader. The new stress test driver, test_kmod, is only enabled as a module right now. It should be possible to load this as built-in and load tests early (refer to the force_init_test module parameter), however since a lot of test can get a system out of memory fast we leave this disabled for now. Using a system with 1024 MiB of RAM can *easily* get your kernel OOM fast with this test driver. The test_kmod driver exposes API knobs for us to fine tune simple request_module() and get_fs_type() calls. Since these API calls only allow each one parameter a test driver for these is rather simple. Other factors that can help out test driver though are the number of calls we issue and knowing current limitations of each. This exposes configuration as much as possible through userspace to be able to build tests directly from userspace. Since it allows multiple misc devices its will eventually (once we add a knob to let us create new devices at will) also be possible to perform more tests in parallel, provided you have enough memory. We only enable tests we know work as of right now. Demo screenshots: # tools/testing/selftests/kmod/kmod.sh kmod_test_0001_driver: OK! - loading kmod test kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND kmod_test_0001_fs: OK! - loading kmod test kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL kmod_test_0002_driver: OK! - loading kmod test kmod_test_0002_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND kmod_test_0002_fs: OK! - loading kmod test kmod_test_0002_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL kmod_test_0003: OK! - loading kmod test kmod_test_0003: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0004: OK! - loading kmod test kmod_test_0004: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0005: OK! - loading kmod test kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0006: OK! - loading kmod test kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0005: OK! - loading kmod test kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0006: OK! - loading kmod test kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS XXX: add test restult for 0007 Test completed You can also request for specific tests: # tools/testing/selftests/kmod/kmod.sh -t 0001 kmod_test_0001_driver: OK! - loading kmod test kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND kmod_test_0001_fs: OK! - loading kmod test kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL Test completed Lastly, the current available number of tests: # tools/testing/selftests/kmod/kmod.sh --help Usage: tools/testing/selftests/kmod/kmod.sh [ -t <4-number-digit> ] Valid tests: 0001-0009 0001 - Simple test - 1 thread for empty string 0002 - Simple test - 1 thread for modules/filesystems that do not exist 0003 - Simple test - 1 thread for get_fs_type() only 0004 - Simple test - 2 threads for get_fs_type() only 0005 - multithreaded tests with default setup - request_module() only 0006 - multithreaded tests with default setup - get_fs_type() only 0007 - multithreaded tests with default setup test request_module() and get_fs_type() 0008 - multithreaded - push kmod_concurrent over max_modprobes for request_module() 0009 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type() The following test cases currently fail, as such they are not currently enabled by default: # tools/testing/selftests/kmod/kmod.sh -t 0008 # tools/testing/selftests/kmod/kmod.sh -t 0009 To be sure to run them as intended please unload both of the modules: o test_module o xfs And ensure they are not loaded on your system prior to testing them. If you use these paritions for your rootfs you can change the default test driver used for get_fs_type() by exporting it into your environment. For example of other test defaults you can override refer to kmod.sh allow_user_defaults(). Behind the scenes this is how we fine tune at a test case prior to hitting a trigger to run it: cat /sys/devices/virtual/misc/test_kmod0/config echo -n "2" > /sys/devices/virtual/misc/test_kmod0/config_test_case echo -n "ext4" > /sys/devices/virtual/misc/test_kmod0/config_test_fs echo -n "80" > /sys/devices/virtual/misc/test_kmod0/config_num_threads cat /sys/devices/virtual/misc/test_kmod0/config echo -n "1" > /sys/devices/virtual/misc/test_kmod0/config_num_threads Finally to trigger: echo -n "1" > /sys/devices/virtual/misc/test_kmod0/trigger_config The kmod.sh script uses the above constructs to build different test cases. A bit of interpretation of the current failures follows, first two premises: a) When request_module() is used userspace figures out an optimized version of module order for us. Once it finds the modules it needs, as per depmod symbol dep map, it will finit_module() the respective modules which are needed for the original request_module() request. b) We have an optimization in place whereby if a kernel uses request_module() on a module already loaded we never bother userspace as the module already is loaded. This is all handled by kernel/kmod.c. A few things to consider to help identify root causes of issues: 0) kmod 19 has a broken heuristic for modules being assumed to be built-in to your kernel and will return 0 even though request_module() failed. Upgrade to a newer version of kmod. 1) A get_fs_type() call for "xfs" will request_module() for "fs-xfs", not for "xfs". The optimization in kernel described in b) fails to catch if we have a lot of consecutive get_fs_type() calls. The reason is the optimization in place does not look for aliases. This means two consecutive get_fs_type() calls will bump kmod_concurrent, whereas request_module() will not. This one explanation why test case 0009 fails at least once for get_fs_type(). 2) If a module fails to load --- for whatever reason (kmod_concurrent limit reached, file not yet present due to rootfs switch, out of memory) we have a period of time during which module request for the same name either with request_module() or get_fs_type() will *also* fail to load even if the file for the module is ready. This explains why *multiple* NULLs are possible on test 0009. 3) finit_module() consumes quite a bit of memory. 4) Filesystems typically also have more dependent modules than other modules, its important to note though that even though a get_fs_type() call does not incur additional kmod_concurrent bumps, since userspace loads dependencies it finds it needs via finit_module_fd(), it *will* take much more memory to load a module with a lot of dependencies. Because of 3) and 4) we will easily run into out of memory failures with certain tests. For instance test 0006 fails on qemu with 1024 MiB of RAM. It panics a box after reaping all userspace processes and still not having enough memory to reap. [arnd@arndb.de: add dependencies for test module] Link: http://lkml.kernel.org/r/20170630154834.3689272-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170628223155.26472-3-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Jessica Yu <jeyu@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>